Joint DOA and frequency estimation with sub-Nyquist sampling

Inspired by the concept of sub-Nyquist sampling, in this paper, a receiver architecture of sensor arrays for jointly estimating the frequency and direction-of-arrival (DOA) of the narrowband far-field signals is presented. In particular, our contribution is threefold. (i) First, we propose a time-space unionized signal reception model for array signals, where sub-Nyquist sampling techniques can be used. (ii) Second, based on the reception model, two algorithms for jointly estimating frequency and DOA are proposed. One is based on a trilinear decomposition by the third-order tensor theory and the other is based on subspace decomposition. (iii) Third, we derive the corresponding Cramér-Rao Bound (CRB) for such a model and analyze the computational complexity of the proposed algorithms as well. Simulation results demonstrate that the estimation performance of our proposed algorithms based on the receiver architecture closely match the CRBs with respect to the noise levels, the branch number and the source number.